Cyclopentanophenanthrene derivatives and compounds



CYCLOPEN TAN OPHENAN THRENE AND COMPOUNDS Carl Djerassi, George Rosenkranz, and Luis L. Miramontes, Mexico City, Mexico, assignors to Syntex S. A., Mexico City, Mexico, a corporation of Mexico No Drawing. Application October 5, 1951, Serial No. 250,036

Claims priority, application Mexico June 4, 1951 8 Claims. (Cl. 260-397.3)

DERIVATIVES The present invention relates to certain novel cyclopentanophenanthrene derivatives and to processes for the production thereof.

More particularly the present invention relates to a novel A -19-no1pregnen-3,20-dione (19-no1progesterone), a novel homologue of progesterone lacking the angular methyl group in position 10 of progesterone and having superior progestational activit A l9-no1progesterone has been disclosed and previously synthesized by Ehrenstein (J. Org. Chem. 9, 435 (1944). The compound obtained by Ehrenstein is described as a resin (a) +89 supposedly consisting of a mixture of isomers with a predominance of the 14-iso-17-is0 configuration (Ehrenstein et a1., Chem. Rev. 42, 475 (1948); J. Org. Chem. 16, 355 (1951); Plattner et al., Helv. Chim. Acta., 31, 249 (1948).

In accordance with the present invention a 19-norprogesterone has been obtained which is melting point and an entirely difierent optical rotation, (a) +l47, the present compound possesses the same natural configuration at C14 and C17 as progesterone. Further, it is believed that the configuration at the 10 carbon atom is ,8, since this is the most stable configuration produced in accordance with the hereinafter set forth process. Further, the novel 19- norprogesterone of the present invention has a progestational activity from 3-5 times greater than that of progesterone itself. In addition to the high biological and therapeutical potency of the present novel compound, it is further desired to point out that the l9-norprogesterone is a valuable intermediate for the total synthesis of progestational and cortical hormones.

The novel process according to the present invention may form a part of a total synthesis of 19-norprogesterone, since the starting material, 3-alkyloxy-17-acety1-1,3,5( 10)- estratriene, is conventionally obtained by the etherification of the known 3-hydroxy-l7-acetyl-1,3,5(10)-estratriene (Djerassi, Rosenkranz, Iriarte, Berlin and Romo, J. Am. Chem. Soc. 73, 1523 (1950), this compound having also been prepared from estrone, (Velluz 'and Muller, Bull. Soc. Chim. France, 166 (1950). Since estrone has been In addition, the present invention relates to certain other novel intermediates possessing the A -19-norpregnen structure and the A -19-norpregnen structure. The novel process according to the present invention may be illustrated by the following equation:

2,759,951 Patented Aug. 21, 1956 CH: CHI (J 0 (lH-OH Reduction alkali metal R O ammonia R O l Rearrangement acid CH: CH3 (l=0 H-O R H H Oxidation In the above equation R is a suitable alkyl group, preferably a lower alkyl group,

such as a mixture of benzene and ether.

The product was A -19-norpregnen-20-ol-3-one.

The corresponding tional acylation with an organic acid, as for example acetic or propionic to produce the corresponding ZO-acetate or propionate.

The A -19-norpregnen-20-ol-3-one could be oxidized with a suitable oxidizing agent commonly used for oxidation of the 20-hydroxy group of steroids, such as chromic acid to produce the 19-norprogesterone.

Although the above process has been described starting with a 3-alkyloxy-17-acetyl-1,3,5(10)-estratriene, it is within the broad scope of the present invention to utilize for a starting material any corresponding compound. For example, compounds could be utilized having double bonds at positions 6,7; 7,8; 9,11; or 11,12 of the molecule. Further, the steroid nucleus could be substituted with hydroxy or keto groups, the corresponding esters or ethers of the hydroxy groups at positions 11, 12, 17, and/ or 21 of the molecule. Upon reaction with these derivatives of the starting compounds indicated the corresponding 3 alkyloxy-A estradiene derivatives would be prepared and from the estradiene derivatives the corresponding A -19-norpregnen-20-ol-3-one derivatives and from this last type of compound the corresponding A -19-norpregnen-3,2O-dione derivative.

The following specific examples serve to illustrate but are not intended to limit the present invention:

EXAMPLE I A -19-nor-3-methoxy-ZO-hydroxypregnadiene 8 g. of lithium metal (wire) were dissolved in 1 1t. of liquid ammonia in a Dewar flask provided with a mechanical stirrer, and in a period of approximately minutes, a solution of 1 g. of 3-methoxy-17-acetyl-1,3,5- estratriene in 40 ml. of absolute ethanol and 200 ml. of anhydrous ether was added drop by drop, followed by the addition of 30 ml. more of absolute ethanol. After the blue color had disappeared, 50 ml. of water were added.

The ammonia was left to evaporate overnight at room temperature, the residue was collected with water and extracted with a mixture of ether and ethyl acetate. The extract was washed until neutral, dried and evaporated to dryness. 0.86 g. of a pale yellow oil was obtained. A sample was crystallized from acetone, giving the enol ether of A -19-nor-3-methoxy-20-hydroxypregnadiene, melting point 135-l38 C. (a) 1-88. It showed no selective absorption in the ultraviolet and the infrared showed the presence of a free hydroxy group.

EXAMPLE II Working under the conditions described in Example I, but using 8 g. of sodium instead of lithium, 0.84 g. of oil was obtained, which, on crystallization from acetone, gave crystals identical to the ones obtained according to Example I.

EXAMPLE III A -1 9-n0rpregnen-20-0l-3-0ne The oil obtained according to Example I (0.86 g.) was lower alkyloxy-ZO-hydroxy 4.35), infrared carbonyl band at 1736 cm.- (acetate) and 1674 cm.- (A -3-ket0); it did not show the band characteristic of free hydroxy groups.

EXAMPLE IV A*-] 9-n0rpregnen-3,ZO-dione (19-n0rpr0gester0ne) 0.65 g. of the product obtained according to Example III (A -19-norpregnen-20-ol-3-one) was dissolved in 15 ml. of glacial acetic acid, and keeping the temperature below 20 C., a solution of 0.15 g. of chromic acid in 1 ml. of water and 5 ml. of acetic acid was added drop by drop. After standing during 90 minutes at room temperature, methanol was added to destroy the excess oxidizing agent and the solution was evaporated to dryness under vacuum (22 mm. Hg The residue was extracted with ether, washed until neutral, dried, evaporated and crystallized from methanol.

Yield 0.54 g., melting point 142-145 C., (a) +l54.

The analytical sample of l9-norprogesterone had a melting point of 144-145 C., (a) +147, ultra-violet maximum at 240 mu (log E 4.26) infrared carbonyl bands at 1706 cm." (20-ketone) and 1674 cm. (A -3-ketone); it showed no free hydroxy band.

We claim:

1. A new process for the reduction of 3-alkyloxy-l7- acetyl-1,3,5(10) estratriene derivatives which comprises reducing the estratriene compound with a solution of alkali metal in liquid ammonia to produce the corresponding 3-alkyloxy-A -estradiene derivative.

2. A new method for the preparation of a 19-norprogesterone comprising reducing a 3-alkyloxy-l7-acetyl- 1,3,5(10)-estratriene compound with an alkali metal in liquid ammonia to produce the corresponding 3-alkyloxy- A -estradiene derivative, thereafter rearranging said estradiene derivative in acid medium to produce a A -19- norpregnen-20-ol-3-one derivative and finally oxidizing the 20-ol compound thus produced to produce the corresponding A -19-norpregnen-3,20-dione compound.

3. A new compound consisting of A -l9-nor-3- pregnadiene.

4. A new compound consisting of A -19-nor-3- methoxy-ZO-hydroxy pregnadiene having a melting point of 135138 C.

5. A new A -norpregnen compound selected from the class consisting of A -norpregnen-20-ol-3-one and 20 low- A -norpregnen-2O-ol-3-one having a melting refluxed during one-half hour with 25 ml. of methanol and 15 ml. of 4N. hydrochloric acid. The reaction mixture was poured in 250 ml. of saturated sodium chloride solution and extracted with four portions of ethyl acetate; the extract was washed with water until neutral, dried and evaporated to dryness. The residue (0.77 g.) was passed through a column of alumina and eluted with benzene-ether (1:1). In this manner, 0.65 g. of colorless crystals were obtained, melting point 160168 C., (u) +44, ultra-violet maximum at 240 mu, (log E 4.26). The product was sufiiciently pure for use in the preparation described in Example IV. The analytical sample of the product A -19-norpregnen-20-ol-3-one was obtained by crystallization from hexane-ethyl acetate, melting point 174-177 C., (a) |-42, ultra-violet maximum at 240 mu, (log E 4.37), infrared bands at 3617 cmr (free hydroxy group) and 1678 cm." (A -3- keto).

The acetate of A -l9-norpregnen-20-ol-3-one was obtained by aeetylation by known methods and crystallized from ethyl acetate; it had a melting point of 178-179? C., (a) +41, ultraviolet maximum at 240 mu (log E er fatty acid esters thereof.

6. A new compound consisting of A -norpregnen-2O- ol-3-one having a melting point of 174177 C.

7. A new compound consisting of the 20-acetate of point of 178- 8. A crystalline A -19-norpregnene-3,20-dione having the following structural formula:

OTHER REFERENCES Fieser et 211. Natural Products Related to Phenanthrene, 3rd ed., pp. 521-22, 544, 620 (1949).

Ehrenstein Nov. 21, 1950 l Ehrenstein Nov. 21, 1950 l 

8. A CRYSTALLINE $4-19-NORPREGNENE-3,20-DIONE HAVING THE FOLLOWING STRUCTURAL FORMULA: 